Door operating mechanism



Dec. 15, 1931. J. E. BANcROFT 1,836,059

DOOR OPERATING MECHANISM Fiied oct. 12, 1928 E71- Y E17/5 /7 /0 Z 830 /7 /8 /0 4/58 llllnmhHumm INVENTOR WITN ESS JAMES EBANCRUFI" @if/1.,? I

ATroRNE Patented Dec. 15, 1931A .UNITED STATES PATE JAMES E. BANCROFT, or DETROIT, :lrIIoIIIGAN,v AssIGnon lTo nooiteivroTIvn coRhroIftAl TIoN, or woRoEsTEn., MASSACHUSETTS, A conI'oitATIoN oF ivIAssAoIIusnTTs' noon ornRATING IaaoIafANIsirIl Application nied'october 12, una."v serial-neg 312,096."

This invention relates to door operating mechanisms, and more particularly to power driven apparatus arranged to open and close doors of the sli'dable type. Y a Doors ofythis type are in common use'in connection with freight elevator shafts, where the service is unusually severe. .The doors are usually of heavy construction, and u hand operation has proven unsatisfactory in most instances.l SuchV power operators ashave heretofore been used have been subject to various disadvantages. Some of these devices cause excessive'slamming of the doors at the end of their .'travel, which produces undesirable noise and increases the cost of maintenance of the entire equipment. Others tend to twist the doors' and cause them to bind in the guides. Still others are expensive and complicated, and are difficult to install in connection with existing doors.

It is accordingly the main object ofi my invention to overcome thesedifculties and to provide a power driven mechanism which will operate slidable doors swiftly and l smoothly without undue friction or noise.

It is a further object of my invention lto provide a door operator which will be simple land inexpensive to manufacture, .and which can be connected to existing installations of sliding doors without altering the doors or their supporting structure. Y

With these and other objects in View, as willbe apparent to those skilled inthe art, my invention resides in the combination of parts set forth in the specification and covered by the claims appended hereto.

Referring to the drawings illustrating one embodiment of my invention, and in which like reference numerals indicate like parts.

Fig. 1 is a front elevation of an installation in connection with doors of the vertically slidable counter-balanced type, the doors being shown in the closed positionand certain parts being broken away for clearness `of illustration;

F ig. 2 is a cross section on the line 2 2 of Fig. 1, and l Fig. 3 is a front elevation showing the position of the mechanism when the doors are open. a

vthe other door will move freight elevator shafts,-l

'between the connecting lThe embodiment illustratedv in the drawy ings comprises a verticalwall 10 provided with arectangular opening 11 therethrough, and a pair of doors 13 and Unmounted on one side of the wall adjacentto the" opening. Door 13 is'arranged doors are slidable verticallyin guides-(not shown), l

abovedoorlet', and both The doors arel connected at'eac'hf I' endby means of flexible members,such as the r cables 16 which pass over` sheaves 17 mounted on brackets 18 on'thewall. `.The cables support the 4weight of the doors, so'that each door acts as a counter-weight for'theother,

andthe doors are prefera ly made of substantially equalweight. JItwill bea-pparent thatwhenever'one door is moved lup or down,

rection. Counter-balanced doorsof this type are frequently used to vprovideAr`l access to and many installa? in lthe opposite" ditions are opened and closed-hundreds of times f a day." Hand operation is slow and laboriousi I In order`to actuatethe doors by powerl provide a power driven-crank 20 anda connecting rod 21.` One end oftheconnecting rod Vsuch heavy doors y is pivoted at 23 to the crank, fand theother A endois pivoted at 24 to one ofthe doors land preferably to the upper door13.- asillu'strat.-

ed.` Theic'rank 20 may bemountedabovefthe opening 11 on theY opposite side of the wall from th'edoors, and" is preferably arranged for rotationrabout an axis perpendicularto the wall. In order to minimize the tendency to twist the doors and cause them to bindin the guides, I locate the pivoted connection 24 on the vertical center line ofthe door lland g near the lower edge thereof. Ihe connectingrod may havean oiset portionV 26y at its lower end (Fig 2.) so as to avoid interference other words, vfor each extreme positionfof rod and the lwall .Torr Y y,'I`he, .worin is driven v y motcrl 33 directly connected thereto.

art.

Fig. 2,' vand attached T prefer to rotate the crank in one direction to open the doors and in the reverse direction to close them, and to mount the crank with its axis odset from the vertical center line of the-doors in a direction. opposite to the direction toward which the crank extends during the maj or part of its travel. For example, from Figs. 1 and 2 it will be apparent that crank 20 will extend to the rightduring the major part of, its travelV from one extreme position to the other, and the axis of the crank is located to the leit of the door Vcenter line. This construction applies force to the-upper door in a substantially vertical direction and reduces thedoors.' f

. Various -meansfor driving the crank may be used-within the scope of inyinventiombut in the preferred embodiment 4illustrated the crank ismounted on the shaft of a worm gear O-which meshes with a worm 31 (Fig. 1). by ka reversible Velectric The motor is suitably connectedfto a source oi electric power, and a limit switch 35 and brake 36 arepreferably utilized to stop the motor automatically asthe doors reach eitherextreme position.`V The limit switch andbrake are merelyindicateddiagrammatically in the drawings, since they form no part of the present invention, and various suitable constructions are well known to those skilledin this p The wormyandgworm gear may be enclosed in a casing 38'wliich is mounted together with the motor on a horizontal support 40. This support is lspaced from the wall as shown in thereto by a bracket 41 at each end. The crank is mounted between the worm gear and the wall, andthe connecting redis pivoted to the crank on that side Ythereofwhich acesthe wall. This construction permits'the connecting rod to move very ,close to thewall, so that the operating force is applied as nearly in line with the door as possible. l f lThe 'operation of my invention will now be apparent from the above disclosure. Assuming the doors to be inthe kclosed position vshown in Fig. 1,'the'motor 33 is started and acts'through the worm and gear to rotate the crank 20 in the direction' oit the arrow' in Fig. 1. The crank was originally on dead center, Vand theV connecting. rod therefore starts the door gradually upward. The door rapidly gains speed, reaches a maximum near 'the halt way point, and then slows down to a gradual stop as the crank reaches the other dead centerV position. During this time the lowerdoor of course is moving downwardly -atthe samevelocity. To close the doors, the

motor is reversed `to drive the crank in the .directi'oriof the arrowin Fig. 2. During the the tendency to `twist Y pendicul'ar closing movement, the doors approximate `simple harmonic motion, the same as during the opening movement.

The invention is inexpensiveto build, and its installation requires. substantially no alteration of the existing structure. It provides swift and silent door operation with a minimum of 1power consumption.

Having thus described my invention, what VT- claimasnew and desire to secure by -Letother end to the door, said parts being so con- Astructed and arranged that the crank 1s substantially at one dead ce'nter'position when the dooris closed and substantially at the open;4 Y v v Y 2. Ari-operating mechanism for a vertical.- ly slidabledoor comprisingl a crankmounted for rotation about an axis substantiallyperto `the vpla-ne of the door, a connecting rod which is pivoted at one end to the crank and-at the other end to the door at a point substantially onthe vertical center line of the door, and power means torotate .thecrank in one direction to open-the door and inthe oppositer direction to yclose the door, said crank -bein'gfrmounted .with its axis offset from the vertical center line of the door in a direction opposite to the direction toward which the crankextends during the major part oit its travel. Y

^ 3.' An operating mechanism for a vertically 'slidabl'e'door comp ising va crank mounted for rotation about an axis substantially perpendicular-.to the plane ci the door, -a connectingrod which is pivoted jat one endL to the crank and at the other end to the door at av point substantially on the vert-ical center line ci" the door, said parts being so. constructsite to the direction toward whichY the crank extends Vduring-the ma]or part of its travel.

Zi. `A closurev comprising a pair of vertically -slidable .doors of substantially equal weight and arranged one above the other,

means including` a flexible member connecting thje doors and so arranged thateach door r acts as a counterweight for the other, a crank .mounted vfor rotation about an axissubstan- Y tially perpendicular to the plane'of the doors,

power means connected to the crank to `rotate f `1 85 other dead centerl position when the door is -lll the same, and a connecting rod which is pivoted at one end to the crank and at the other end to the upper door.

A closure comprising a pair of vertically slidable doors of substantially equal weight and arranged one above the other, means in- Y cluding a flexible member connecting the doors and so arranged that each door acts as a counterweight for the other, a crank y mounted above the doors and rotatable about an axis, substantially perpendicular to the plane of the doors, power means connected to the crank to rotate the same, and a connecting rod which is pivoted at one end to the crank and at the other end to the upper door at a point substantially on the vertical center line of the door and near the lower edge thereof.

6. A closure comprising a vertically slidable door, a crank mounted above the door and rotatable about an axis substantially'perpen` dicular to the plane of the door, power means connected to the crank to rotate the same, and a connecting rod which is pivoted at one end other side of the wall and spacedtherefrom, a worm gearV on said supportv and arranged for rotation about an axis perpendicular to the wall, a worm in Vmesh with said worm gear, a motor connected to drive said worm, a crank between the worm gear and wall, connections between the rcrank and the worm gear v whereby they both rotate together, and a connecting rod which is/pivoted at one end 'to the crank on that' side of the crank'which faces the wall and at the otherend to the upper door at a point substantially on the vertical center line lower edge thereof, structed and arranged that the crank will be on one dead center when the doors are closed and on the other dead center'when the doors are open. f

Signed at Detroit, Michigan, this 8th day of October, 1928;

to the crank and at the other end to the door l at a point substantially on the vertical center line of the door and near the lower edge thereof, said cra-nk and connecting rod beingso arranged that the crank will be on one dead center when the door is other dead center when the door is open.

closure comprising a pair of vertically slidable doors mounted on oneside of av wall having an opening therethrough, said doors being located one above the other, connections between the doors so arranged that each door acts as a counterweight for the Y on the other side of v other, a crank mounted the wall above the opening and arranged for rotation about an axis substantially perpendicular to the plane of the doors, a motor connected to rotate the crank, and a connecting rod which is pivoted at one end to the crank and at the other end to the upper door.

closure comprising avertically slidable door mounted on one side of a wall having an opening therethrough, a support mounted above the opening on the other side of the wall and spaced therefrom, a worm gear on said support and arranged for rotation about an axis perpendicular to the wall, a worm in mesh with said worm gear, a motor connected to drive said worm, a crank located betweenr the worm gear and the wall, connections between the crank and the worm gear whereby they both rotate together, and a connecting rod which is pivoted at one end to the crank 'ind at the other end to the lower part of said oor.

9. A closure comprising a pair of vertically didable doors mounted on one side of a wall iaving an opening therethrough, said doors )eing located one above the other, connecions between the doors so arranged that each [oor acts as a counterweight for the other, i support mounted above the opening on the closed and on the` I ion JAMES E. BANcRoiTf. c

of thedoor and near the l said parts being so con- 

